MIAMI (CBS4) – David Rivera saw his dream of being a United States Congressman fulfilled when he was sworn into office Wednesday afternoon in the nation’s capital. But a growing Miami-Dade State Attorney’s investigation of Rivera, and his sources of income, hung as a cloud over the day’s festivities.

Rivera began his first day as a member of Congress on the defensive. In an interview early Wednesday morning with CBS4’s Michael Williams, Rivera was forced to explain why claimed he didn’t receive any money from a company operated by his mother — but now admits taking $137,000 in loans.

WILLIAMS: “You sat there and said to me, `I did not take a single penny from Millennium and yet you did take a six figure loan from Millennium.”

RIVERA: “Well I don’t remember, I don’t know how you posed the question. My understanding was you were asking if I ever received any payments, any income from any source associated with it.”

WILLIAMS: “No, I asked if you took a single penny from Millennium.”

RIVERA: “Well, I haven’t taken a single penny of income from Millennium or any other source associated with the 2008 referendum.”

Rivera argued that since a loan is different from income he wasn’t really changing his story.

As the CBS4 I-Team first reported last month, Rivera had arranged for Millennium to be secretly paid more than $500,000 by Flagler Dog Track for Rivera’s work on the 2008 referendum that brought casino style slot machines to Miami-Dade county tracks.

Rivera’s 70-year-old mother, Daisy, is the vice-president, secretary and treasurer of Millennium. And his godmother, Ileana Medina, is the company’s president.

Rivera gave a rambling and confused answer when he was asked why he arranged for all of the money he earned from running the slots campaign to go to Millennium.

“Actually that was an arrangement between Flagler Dog Track and Millennium,” Rivera argued. “There was a contract, as is very routine and common, that they may look for vendors and that was a vendor that was recommended. They designated me as the point person representing them. That’s exactly what happened.”

Actually, that is not what happened. According to the owners of Flagler Dog Track, it was Rivera’s idea to route all of his money through Millennium. They never even heard of Millennium. And for its part, Millennium did not even exist when Rivera and Flagler officials began negotiating the agreement.

And it is because Rivera’s answers don’t make much sense that prosecutors are widening their investigation.

Rivera also refused to shed any light on another strange aspect of the case. As CBS4 News reported last month, in addition to the $510,000 Flagler has already paid to Millennium, the dog track owes Millennium another $500,000 for Rivera’s work.

Flagler’s attorney said the only reason Flagler hasn’t paid the money is that Millennium hasn’t requested it.

Asked why his mother and godmother’s company hasn’t requested the $500,000, Rivera said: “I think that is a better question posed to them.”

Nevertheless, as Rivera settles into his new office he vows to be as honest in his new position as he has been in the past.

“I’ve always been above board on my stance on issues and that will certainly continue going forward,” he said.